- Efficient Water Oxidation Using CoMnP Nanoparticles
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The development of efficient water oxidation catalysts based on inexpensive and Earth-abundant materials is a prerequisite to enabling water splitting as a feasible source of alternative energy. In this work, we report the synthesis of ternary cobalt mang
- Li, Da,Baydoun, Habib,Verani, Cláudio N.,Brock, Stephanie L.
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- ThMnPnN (Pn = P, As): Synthesis, Structure, and Chemical Pressure Effects
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Mn-based ZrCuSiAs-type pnictides ThMnPnN (Pn = P, As) containing PbO-type Th2N2 layers were synthesized. The crystal and magnetic structures are determined using X-ray and neutron powder diffraction. While neutron diffraction indicates a C-type antiferromagnetic state at 300 K, the temperature dependence of the magnetic susceptibility shows cusps at 36 and 52 K respectively for ThMnPN and ThMnAsN. The susceptibility cusps are ascribed to a spontaneous antiferromagnetic-to-antiferromagnetic transition for Mn2+ moments, which is observed for the first time in Mn-based ZrCuSiAs-type compounds. In addition, measurements of the resistivity and specific heat suggest an abnormal increase in the density of states at the Fermi energy. The result is discussed in terms of the internal chemical pressure effect.
- Cao, Guang-Han,Feng, Zhifa,Hu, Bingfeng,Jing, Qiang,Li, Baizhuo,Liu, Bo,Liu, Zichen,Luo, Huiqian,Ma, Jie,Mao, Huican,Mei, Yuxue,Ren, Qingyong,Ren, Zhi,Shao, Yeting,Sun, Yuping,Tan, Shugang,Wang, Cao,Wang, Zhicheng,Xia, Yuanhua,Zhang, Fuxiang
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- De Haas–Van Alphen experiment and Fermi surface properties in field-induced ferromagnetic state of MNP
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MnP is a prototype 3d-itinerant magnet but still a compound under considerable study. This is based on the characteristic magnetic phases including the helical, cone, and fan structures and a variety of phase transitions with a Lifshitz tricritical point. The Fermi surface properties, however, have been scarcely studied. We have thus carried out a de Haas–van Alphen (dHvA) experiment using a high-quality single-crystal sample grown by the Sn-flux method. Many dHvA branches are observed, ranging from 2.8 × 106 to 9.45 × 107 Oe. The corresponding cyclotron effective masses are moderately heavy, 0.7 ? 10m0 (m0: rest mass of an electron), reflecting itinerant Mn-3d electrons.
- Kawakatsu, Shoya,Kakihana, Masashi,Nakashima, Miho,Amako, Yasushi,Nakamura, Ai,Aoki, Dai,Takeuchi, Tetsuya,Harima, Hisatomo,Hedo, Masato,Nakama, Takao,ōnuki, Yoshichika
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- Growth of bulk single-crystal MnP helimagnet and its structural and NMR characterization
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Bulk single crystals of manganese phosphide (MnP) were grown from melt at 1 GPa and 1200 °C by using a cubic-anvil, high-pressure, and high-temperature technique. The obtained black colored crystals exhibit a plate-like morphology, with flat surfaces and maximum dimensions up to ~4 × 2 × 0.5 mm3. The orthorhombic crystal structure was confirmed by X-ray diffraction [Pnma, 62, Z = 4, a = 5.2510(4) ?, b = 3.1670(3) ?, c = 5.9098 (4) ? and V = 98.279(14) ?3]. Temperature-dependent magnetization measurements reveal the occurrence of two successive transitions: a paramagnetic to ferromagnetic transition at Tc = 290.5 K and the development of a double helimagnetic order at Ts = 44.5 K. Zero-field 31P NMR measurements in the FM and in the screw-spin AFM state show prominent features, which are compared with previous experimental data and theoretical calculations. The relatively large crystals obtained here open up new possibilities for further explorations of this interesting material.
- Zhigadlo, Nikolai D.,Barbero, Nicolo,Shiroka, Toni
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p. 1027 - 1034
(2017/08/02)
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- A tetragonal polymorph of SrMn2P2 made under high pressure-theory and experiment in harmony
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Following the predictions of total energy calculations, a tetragonal SrMn2P2 phase is proposed and successfully formed under high pressure. At ambient pressure, SrMn2P2 adopts the primitive trigonal La2O3 structure type (space group P3m1). However, the results of total energy calculations indicate that SrMn2P2 should be more stable in the tetragonal ThCr2Si2 structure type (space group I4/mmm) than in its known trigonal structure, thus motivating our synthetic experiments. Guided by these calculations, a new tetragonal polymorph of SrMn2P2 was found under the relatively mild conditions of 5 GPa applied pressure at a temperature of 900 °C through the transformation of the ambient pressure trigonal form. The new polymorph has the body centered tetragonal ThCr2Si2 structure type, as predicted. The electronic structure calculations indicate the likelihood of antiferromagnetic, semiconducting properties for the high pressure SrMn2P2 phase.
- Xie, Weiwei,Winiarski, Micha? J.,Klimczuk, Tomasz,Cava
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p. 6835 - 6838
(2017/07/10)
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- Composition and structural perfection of (AIII,Mn)BV and MnBV (A = Ga, In; B = Sb, As, P) nanolayers
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We have determined the elemental composition of laser-deposited (Ga,Mn)Sb, (In,Mn)As, MnP, MnAs, and MnSb layers. The InMnAs layers were not single-phase and contained MnAs clusters. Active Ga and Mn diffusion to the substrate and arsenic diffusion from the substrate during the GaMnSb growth process is accompanied by the formation of a GaMnAs intermediate layer. Pleiades Publishing, Ltd., 2012.
- Dunaev,Zvonkov,Danilov,Vikhrova,Drozdov,Drozdov,Suchkov
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p. 553 - 558
(2012/07/13)
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- Li reaction mechanism of MnP nanoparticles
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MnP nanoparticles (MnPs) with a particle size of 7 phases. During lithium dealloying (charging to 2 V), LiMnP phase was turned into the LiP and LiP5 phases.
- Sim, Soojin,Cho, Jaephil
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p. A669-A672
(2012/05/31)
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- Preferential crystallographic alignment in polycrystalline MnP
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The existence of preferential crystallographic alignment in hot pressed and die upset manganese phosphide (MnP) was investigated using magnetic measurements and electron backscatter diffraction (EBSD). Pole figures calculated from the EBSD data show that die upsetting causes the 〈1 1 0〉 directions to align preferentially along the die upset (DU) direction with the 〈0 0 1〉 direction preferentially perpendicular to the DU direction. Magnetic measurements show that the die upsetting can reduce the saturation field relative to that of a similar sample with randomly oriented grains. Since the low-field magnetocaloric effect in single crystals of MnP has been shown to be greatest along the 〈0 1 0〉 direction and smallest along the 〈1 0 0〉 direction, this technique offers a means to achieve the advantages of single crystal alignment with the economy of using bulk processing techniques on polycrystalline material. The peak magnetic entropy change measured with the field applied along the DU direction in the DU sample was 3%, 5%, and 8% greater than the peak entropy change of a randomly oriented powder at fields of 2.0, 1.0, and 0.5 T, respectively.
- Booth, Ryan A.,Marinescu, Melania,Liu, JinFang,Majetich, Sara A.
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p. 2571 - 2574
(2010/08/21)
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- Synthesis of InP nanofibers from tri(m-tolyl)phosphine: An alternative route to metal phosphide nanostructures
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The synthesis of InP nanofibers via a new Ullmann-type reaction of indium nanoparticles with tri(m-tolyl)phosphine (P(PhMe)3) was typically performed to illustrate an alternative route for the preparation of nanostructured metal phosphides, including III-V (13-15) and transition-metal phosphides. Triarlyphosphine compounds such as other two tri(m-tolyl)phosphine isomers, diphenyl(p-tolyl)phosphine, and triphenylphosphine were comparably employed to synthesize InP nanocrystals. From the aspect of the carbonization of triarlyphosphines, Raman spectroscopy and thermo-gravimetric analysis (TGA) investigations of the InP products showed that the stability of these triarlyphosphines conformed to the order of tri(p-tolyl)phosphine ≈ tri(o-tolyl)phosphine 3) 3 (typically see: J. M. Nedeljkovic, O. I. Micic, S. P. Ahrenkiel, A. Miedaner and A. J. Nozik, J. Am. Chem. Soc., 2004, 126, 2632) and P(C8H 17)3 (C. Qian, F. Kim, L. Ma, F. Tsui, P. D. Yang and J. Liu, J. Am. Chem. Soc., 2004, 126, 1195) according to the difference in preparative temperature for phosphide synthesis. Raman and photoluminescence properties of the as-synthesized InP nanocrystals were further studied, and the synthetic mechanism of our method was reasonably investigated by GC-MS analysis. Moreover, the current route was successfully extended to prepare GaP, MnP, CoP and Pd5P2 nanocrystals. The Royal Society of Chemistry 2010.
- Wang, Junli,Yang, Qing,Zhang, Zude,Li, Tanwei,Zhang, Shuyuan
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p. 227 - 233
(2010/03/02)
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- Next-nearest neighbour contributions to P 2p3/2 X-ray photoelectron binding energy shifts of mixed transition-metal phosphides M1-xM′xP with the MnP-type structure
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X-ray photoelectron (XPS) and X-ray absorption (XANES) spectroscopic measurements have been made for several series of mixed transition-metal phosphides M1-xM′xP (Co1-xMnxP, Mn1-xVxP, and Co1-xVxP), which adopt the MnP-type structure (M is more electronegative than M′). The P 2p binding energy shifts displayed by the mixed metal phosphide members do not follow the trend shown by the simple binary phosphides, a deviation which arises from the contribution of next-nearest neighbour effects operating on the primary photoemission site. The magnitude of this contribution can be derived from a simple charge potential model taking the metal electronegativity differences into account. It is suggested that these next-nearest neighbour contributions induce a charge transfer between the two dissimilar metals via metal-metal bonding, which modifies the Madelung potential experienced at the photoemission site. This charge transfer has been confirmed by analysis of the Co 2p XPS spectra as well as the P and Mn K-edge XANES spectra.
- Grosvenor, Andrew P.,Cavell, Ronald G.,Mar, Arthur
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p. 2702 - 2712
(2008/10/09)
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- Self-assembled nanowhiskers grown by MBE on InP(001) surface
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Ge and MnP nanowhiskers were synthesized by molecular-beam epitaxy technique on InP(001) surface concurrently. The growth of Ge nanowhiskers is found to be assisted by Mn-based nanocluster-mediated vapour-liquid-solid mechanism of growth, whereas the grow
- Bouravleuv, Alexei,Minami, Kazuyuki,Ishibashi, Takayuki,Sato, Katsuaki
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p. 2793 - 2799
(2008/10/09)
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- Epitaxial MnP thin films: epitaxial growth, magnetic and electrical properties
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We have grown 500 ? MnP on undoped GaAs(1 0 0) substrate using solid-source molecular beam epitaxy. In order to characterize the crystal structure of MnP, we performed in-situ reflection high energy electron diffraction and θ-2θ XRD X-ray diffraction studies. From the measurements of superconducting quantum interference device, Quantum Design, MnP thin film shows ferromagnetic ordering at around 291.5 K. It shows a metallic resistivity in MnP thin film.
- Choi, Jeongyong,Choi, Sungyoul,Sohn,Park, Hyoyeol,Park, Yongsup,Park, Hyun-Min,Hong,Cho, Sunglae
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p. e112-e114
(2008/10/09)
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- Generalized synthesis of metal phosphide nanorods via thermal decomposition of continuously delivered metal-phosphine complexes using a syringe pump
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We synthesized uniform-sized nanorods of transition metal phosphides from the thermal decomposition of continuously delivered metal-phosphine complexes using a syringe pump. MnP nanorods with dimensions of 8 nm × 16 nm and 6 nm × 22 nm sized were synthesized by the thermal decomposition of Mn-TOP complex, which was prepared from the reaction of Mn2(CO)10 and tri-n-octylphosphine (TOP), using a syringe pump with constant injection rates of 10 and 20 mLVh, respectively. When Co-TOP complex, which was prepared from the reaction of cobalt acetylacetonate and TOP, was reacted in a mixture solvent composed of octyl ether and hexadecylamine at 300 °C using a syringe pump, uniform 2.5 nm × 20 nm sized Co2P nanorods were generated. When cobaltocene was employed as a precursor, uniform Co2P nanorods with 5 nm × 15 nm were obtained. When Fe-TOP complex was added to trioctylphosphine oxide (TOPO) at 360 °C using a syringe pump and then allowed to age at 360 °C for 30 min, uniform-sized FeP nanorods with an average dimension of 12 nm × 500 nm were produced. Nickel phosphide (Ni2P) nanorods with 4 nm × 8 nm were synthesized successfully by thermally decomposing the Ni-TOP complex, which was synthesized by reacting acetylacetonate [Ni(acac)2] and TOP. We measured the magnetic properties of these nanorods, and some of the nanorods exhibited different magnetic characteristics compared to the bulk counterparts.
- Park, Jongnam,Koo, Bonil,Yoon, Ki Youl,Hwang, Yosun,Kang, Misun,Park, Je-Geun,Hyeon, Taeghwan
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p. 8433 - 8440
(2007/10/03)
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- Ferromagnetism above room temperature in bulk sintered gallium phosphide doped with manganese
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Evidence for ferromagnetism in bulk sintered gallium phosphide (GaP) doped with 3% manganese, having a Curie temperature of 600 K considerably higher than previous observations, is obtained using ferromagnetic resonance (FMR) and AC magnetization measurements. The field position and line width of the resonance showed a strong temperature dependence characteristic of FMR spectra. A non-resonant derivative signal centered at zero field was also observed starting at 600 K further confirming high temperature ferromagnetism. AC magnetization measurements also show the existence of ferromagnetism at high temperature. Published by Elseiver Ltd.
- Owens, Frank J.
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p. 793 - 796
(2008/10/09)
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- Examination of the bonding in binary transition-metal monophosphides MP (M = Cr, Mn, Fe, Co) by X-ray photoelectron spectroscopy
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The binary transition-metal monophosphides CrP, MnP, FeP, and CoP have been studied with X-ray photoelectron spectroscopy. The shifts in phosphorus 2p 3/2 core line binding energies relative to that of elemental phosphorus indicated that the de
- Grosvenor, Andrew P.,Wik, Stephen D.,Cavell, Ronald G.,Mar, Arthur
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p. 8988 - 8998
(2008/10/09)
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- Synthesis of MnP Nanocrystals by Treatment of Metal Carbonyl Complexes with Phosphines: A New, Versatile Route to Nanoscale Transition Metal Phosphides
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The reaction of Mn2(CO)10 with P(SiMe3)3 in coordinating solvents at T ≥ 220 °C yields low polydispersity, highly crystalline MnP nanoparticles for the first time. The effect of dimensional limiting has resulted in the stabilization of a ferromagnetic ground state at low temperatures, rather than the metamagnetic state observed in bulk (microcrystalline) MnP. The synthetic methodology reported here is demonstrated to be general for a number of different metals and phosphine sources. Copyright
- Perera, Susanthri C.,Tsoi, Georgy,Wenger, Lowell E.,Brock, Stephanie L.
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p. 13960 - 13961
(2007/10/03)
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- Interactions of titanium and phosphorus with vanadium, chromium, or manganese
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An X-ray crystallographic study of interactions in the Ti-(V, Cr, Mn)-P systems for phosphorus mole fractions between 0 and 0.50 is reported. Isothermal sections of the phase diagrams at a level of 1070 K are constructed. Solid systems are formed in all systems: (Ti,V)3P, Ti3.0-2.4Cr0-0.6P, and Ti3.0-2.2Mn0-0.8P (Ti3P structure type); Cr3.0-1.9Ti0-0.3P and Mn3.0-1.9Ti0-1.1P (Ni3P structure type); V2.0-0.8Ti0-1.2P (anti-PbCl2); Mn2.0-1.0Ti0-1.0P (Fe2P); Ti1.0-0.8V0-0.2P, Ti1.0-0.8Cr0-0.2P, and Ti0-0.75Mn0-0.25P (TiAs); and Cr1.00-0.88Ti0-0.12P and Mn1.0-0.9Ti0-0-1P (MnP). In the Ti-Cr-P system, a new compound is found. This compound is homogeneous for Ti1.2-0.5Cr0.8-1.5P compositions. The structure of this compound for the composition TiCrP was solved by the powder method: Fe2P structure type, a = 0.6407(1) nm, c = 0.3311 (1) nm; R = 0.093.
- Lomnitskaya
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p. 207 - 211
(2008/10/08)
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- Electronic structure of MnSb and MnP
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We have investigated the valence-band and conduction-band electronic structure of MnSb and MnP by means of ultraviolet photoemission and inverse-photoemission spectroscopies. The photoemission and inverse-photoemission spectra are qualitatively consistent
- Okuda,Senba,Sato,Shimada,Namatame,Taniguchi
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p. 657 - 660
(2008/10/08)
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- Spin-waves in MnP
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Spin-waves in MnP have been measured by means of neutron inelastic scattering at various temperatures. Dispersion relation along a-axis exhibits anomalous wave vector and temperature dependences, while the quadratic q dependence was observed along both b and c-axis. The characteristic feature of the spin-wave dispersion relations agree qualitatively with those predicted on analogy with rare earth metals.
- Todate, Yoshiei,Yamada, Kazuyoshi,Endoh, Yasuo,Ishikawa, Yoshikazu
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